The following background information may present examples of specific aspects of the prior art (e.g., without limitation, approaches, facts, or common wisdom) that, while expected to be helpful to further educate the reader as to additional aspects of the prior art, is not to be construed as limiting the present invention, or any embodiments thereof, to anything stated or implied therein or inferred thereupon.
It is known that gold extraction or recovery from its ores may require a combination of comminution, mineral processing, hydrometallurgical, and pyrometallurgical processes to be performed on the ore. Often, the gold is part of an aggregate containing sand, gravel, small rocks, and various minerals, such as quartz. In this aggregate, there are usually large nuggets of gold and smaller particles of gold, such as gold flakes. These smaller gold particles, i.e. one millimeter or less, can be difficult to separate from other small particles, such as sand and gravel.
Generally, the aggregates that contain gold nuggets and flakes include sand, and specifically heavy sand. The heavy sand may contain gold flakes and other small gold particles so that more refined separation is necessary. Conventionally, the separation of the heavy sand away from the gold is by panning. In such panning, great care is used if little gold is wasted.
Gold panning is a simple process that relies on agitation of the sand, gravel, and gold to induce separation. Once a suitable placer deposit is located, some gravel from it is scooped into a pan, where it is then gently agitated in water and the gold sinks to the bottom of the pan. Materials with a low specific gravity are allowed to spill out of the pan, whereas materials with a high specific gravity sink to the bottom of the sediment during agitation and remain within the pan for examination and collection by the gold panner. Such careful panning is necessarily time-consuming so that the final separation from the portion conserved by the separator is tedious.
Typically, gold mining sites are located in relatively remote areas, or the amount of ore at a given site may be relatively small. In such cases the expense involved in permanent, on-site construction of refining equipment may be greater than the expected return from mining. Thus, there is a real need for an effective, portable unit for gold or other ore refining.
Other proposals have involved separating gold from ore and other particles. The problem with these gold separation devices and methods is that they do not effectively separate smaller particles from smaller gold nuggets and flakes. Even though the above cited gold separation devices and methods meets some of the needs of the market, an assembly and method for gravitationally separating gold from small particles that involves initially sieving for large particle separation, and then applying gravitational separation for separating small particles from the gold, is still desired.